geoff-bristol wrote:( I have never seen european supplliers quoting gram strength ? How does 'gram strength' tie in to varying
amounts of water dilution ? )

Hi Geoff!
Kremer states bloomgrams in their material data sheets. I have emailed Dictum some years ago asking for their glue´s strength, i´m presuming its still the same.

Apart from precise definitions, which are a google click away, the most obvious difference (for me) is working time. I don´t have much to compare - only hide from Kremer and Dictum and bone. Dictum´s higher bloomgram stuff needs more water to get it to the consistency i like (between 1,8 and 2,0 times the amount of water, depending on its intended application), while with kremer´s glue i usually use between 1,5 and 1,7. The consistency is about the same but Kremer´s stuff gels slower and i tend to use it for larger surfaces such as scarf joints, headplates and such. I prefer Dictum´s for brace gluing, dentellones, joining tops and backs, etc. I guess i´m spoiled for choice.

Dictum´s current batch of hide glue is good stuff, you should try it. It´s in granulate form (much quicker at soaking water), light in color and doesn´t smell that strong. Over the years i kind of developed a taste for the smell, actually - if i may disclosure such personal stuff here.
Now Kremer´s. A couple of years back i bought some of their cubes and really liked it. Different smell (maybe easier on the palate), light in color and longer open time, as i´ve said. I believe it was their catalogue number 63010. So i ordered 3 kgs last time and got a very different stuff. Similar smell, but darker, needs only 1,2 times the amount of water to get to the same consistency (which sounds suspiciously low) and takes ages to gel. Glue tests still got wood failure but i´m wary of using the stuff.

May i ask you how´s your batch of Kremer´s glue? (and sorry for the long post)

The stuff I bought from Kremer some 5 years ago was crushed, not cubes. It was high clarity, pretty sure it was 63010. I ordered another batch of the 63010 around a year ago. That came as dark brown cubes, greasy looking. I tested it and wasn't happy with it. It seemed to be very weak and nothing like the earlier batch of 63010, both in colour, form or strength. I returned it. To their credit they sent me some samples that contained various gram strengths, crushed rather than cubes. I've yet to test any of this new stuff because I have a good supply of the Madinter Hosco glue. I'll try post a pic of these various glues that show just how much the stuff varies but you should always test a fresh batch of hide, gluing up various wood types.

On the left is the Kremer hide glue, centre is the Madinter, right is bone/pearl glue. The Madinter is about as clear as I've ever seen hide glue and I've been using hide glue for a few decades. The Kremer glue goes from 180 g strength right through to 440 g although I haven't tested any of these samples yet. It doesn't look as dark, murky or as greasy as the stuff that I sent back. I suspect it will be perfectly fine but I do need to test it.

Dolds wrote:Hi All-I am using hide glue for guitar # 7 for the first time, and have 315 gram hide glue. Can I glue the bridge with this strength glue? I previously used Titebond and I am unsure whether hide glue at 315 gram strength is sufficient.cheers Paul

Hi,
I've been using hide glue for guitars for about 15 years and have done a lot of experimenting and cross-referencing with other luthiers. To briefly summarize: yes gram strength is an indication of the glue's bond strength, but at a point actually translates to weaker joints between wood in practical situations. I found 250 gram to be the upper limit for guitars. At proper dilution you have about 10 seconds to get a warm bridge clamped on. Still not enough time really. It's tempting to add more water, but the far better course is to use a lower gram strength glue. Like Michael said, grades can be mixed to get in-between grades.

I've heard a number of guitar makers say the only bridges that they have had come loose were glued with hide glue, but also found that none of them knew how to properly mix and use hide glue. There's a strong culture in lutherie to overdilute hide glue - probably stemming from the bowed instrument world where instruments need to pop apart easily for repair. High gram strength hide glue watered down to give you a practical working time = brittle joints. 195 - 220 gram glue with the manufacturer recommended amount of water = enough working time and strongest joints.

The glue that is often used for gesso is sturgeon glue. It's very clear, quite strong, and smells awful. I was given a paper bag of the swim bladders by a Russian luthier; you simply dissolve them in water, heat it up and fish out the insoluble parts. I looked it up in Kremer's catalog, and it's much more expensive than hide glue. A couple of cloves masked the smell pretty well, and didn't seem to hurt the strength, but I only mixed up one small batch of it.

I've been using Behlen's 190 gram glue for a long time, with pretty good results. Recently I got some 250 gram stuff at a woodworker's store, labeled 'Brooklyn Tool and Craft'. Aside from gelling fast it's cloudy, and stringy, which makes it hard to clean up. OTOH, I've used it for some center joins and it does seem to be quite strong. I'll try mixing it with the 190 gram stuff when I need working time more than strength.

Mqbenrado
I would say my Kremer is the former one left - its quite light. it would have been from at least 7-8 years ago maybe more. I use it a lot - as you say it seems to have a good open time.
I still have a stock of maybe 5 kilo of various sources - so thats a few instruments worth.